Environmental gamma dose measurements in Mexico City using TLD

The aim of this work is to measure the gamma dose component of environmental radiation in Mexico City's metropolitan area. To perform the TL dosimetry, CaF2:Dy, CaF2:Mn, alpha-Al(2)0(3):C and LiF:Mg, Cu, P crystals were used. The values of environmental gamma dose rate measured ranged between 83 and 112 nGy h(-1) for the time interval going from January to August 1994. Outdoor dose rates were 85 nGy h(-1) +/- 2% for city sites having soil of either volcanic or lacunar origin; this rate was 107 nGy h(-1) +/- 2% at a nearby hill belonging to a volcanic chain. Indoor rates were about 20% higher than outdoor ones at the same location.